Synthesis of functional macromolecules resulting from impartation of various new or improved functionalities to macromolecular compounds is an important problem for macromolecular chemistry. However, there are difficulties in introduction of a functional group which contributes to the aforementioned functionalities to a specific position in a polymer chain utilizing a macromolecular reaction and therefore widely usable methods for synthesizing such functional macromolecules have been awaited. What the present invention intends is to establish such widely usable methods and to create a group of novel functional macromolecular compounds by applying the methods to processes for producing specific functional macromolecules.
For example, polypropylene, which is one of the major three polymers, is excellent macromolecular material having advantages such as being inexpensive, being superior in oil resistance and chemical resistance, and having less environmental load. However, polypropylene is a non-polar macromolecule and it is difficult to introduce a functional group to it. Therefore, it has problems in that it is difficult to reinforce it through its blending with other macromolecules having polar groups because of its less interaction with other polar substances or that it is poor in paintability and adhesiveness.
In recent years researches on new functionalized polypropylene for solving such problems have been done actively. One of such researches involves introduction of functional groups and conversion to diblock copolymers of a polypropylene having vinylidene at one terminal synthesized by a polymerization reaction using a metallocene type catalyst. This is based on the fact that elimination of hydrogen of the β-position occurs selectively at a growing terminal and a vinylidene-type double bond is formed at one terminal if polymerization conditions are properly selected. The monoterminal double bond is very useful for functionalization of polypropylene because it can be converted easily into various functional groups. However, in this case, there are limitations on improvement of physical properties because there is a functional group in a molecular chain only at one terminal. Therefore, no satisfactory new functionalized polypropylene has been obtained yet.
As another example, synthesis of syndiotactic polypropylene has been done recently using polymerization of styrene by use of metallocene type catalysts. Syndiotactic polystyrene has characteristics such as higher melting point, higher crystallinity and better chemical resistance in comparison to widely used polystyrene because of its high stereospecificity. Therefore, development of applications for making use of these characteristics is proceeding actively. However, syndiotactic polystyrene has the defect of being fragile. Although various attempts have been made for overcoming this defect, satisfactory substances have not been obtained yet.
As mentioned above, providing functional macromolecular compounds such as new functionalized polypropylene or polystyrene of improved function by widely usable synthesis methods will lead to development and production of more types of functional macromolecular compounds.